President Trump campaigned hard on the idea that recent U.S. wars for regime change in the Middle East actually made things worse — and at great cost in American blood and treasure. Here's the man who would become America's 45th president at a GOP primary debate in February 2016.

The war in Iraq was a big, fat mistake. They lied. They said there were weapons of mass destruction. There were none. [Donald Trump]

What has happened since then? Why does Trump seem so gung-ho about regime change now?

Make no mistake: There are early rumblings of war afoot. Sure, Secretary of State Mike Pompeo stopped well short of calling for some sort of Iraq-style invasion of Iran in his big Monday speech about how to deal with Tehran in the wake of Trump pulling out of the nuclear deal. But Pompeo did make demands that Tehran will never accept the core requirements of his "better" nuclear deal while also bearing down with the "strongest sanctions in history." The hope seems to be that the Iranian people, with a little coaxing from Uncle Sam, will overthrow their theocratic government on their own. This is unlikely. Indeed, it's not hard to imagine this ending in war.

Remember, the clamor for regime change in Iraq — indeed, the legislation that made it the official policy of the United States — did not start with calls for American military action either. The Trump administration insists it is not going down the same road with Iran, but those assurances ring a bit hollow when coming from the likes of National Security Adviser John Bolton.

Moreover, a combination of unattainable diplomatic goals, an uncertain future for any domestic uprising, and zero tolerance for anything greater than zero uranium enrichment inexorably leads to conflict or capitulation. We know which will be easier to sell to Trump.

This logic has been laid bare in North Korea, where Trump does appear to understand that upfront threats of regime change before the tenuously planned summit (that is now very much in doubt) would be counterproductive to his goal of denuclearization — before suggesting it is exactly "what will take place if we don't make a deal."

Vice President Pence repeated this in an interview with Fox News. "You know, there was some talk of the Libyan model last week," he said. "And as the president made clear, this will only end like the Libyan model ended if Kim Jong Un doesn't make a deal."

The "Libyan model," to which Bolton had also been referring, was almost certainly the 2003 negotiated surrender of Libya's nuclear program rather than the 2011 war that toppled the regime. Trump himself promises to guarantee the survival of Kim Jong Un's government as a condition for disarming. But at this point, it's almost a distinction without a difference. What dictator would want to give up their nuclear weapons only to be attacked and ousted years later, as happened in Libya? Rogue states now view weapons of mass destruction as insurance against regime change.

Trump may exaggerate his prescience about Libya and Iraq. But at various times, he has accurately described the chaos and destruction these interventions have left behind, making stronger the very forces we went over there to combat.

"Say what you want, but then we went out and attacked the wrong country, Iraq had no weapons of mass destruction, we destabilized the Middle East … The Middle East is a mess right now because we destabilized Iraq," Trump has said.

"As bad as Gadhafi was — what comes next in Libya will be worse — just watch," Trump warned on Twitter before it was called Woodstock for jihadists. Of course, Trump has contradicted himself by voicing support for the Libya campaign at various points, but this shows at least some appreciation for the unintended consequences.

In Syria, Trump has tried to keep the country's focus on fighting ISIS rather than getting involved in a multi-front civil war by toppling the loathsome regime of Bashar al-Assad. This has largely been effective despite the pundits' warnings. Trump has thus far confined his interventions against Assad to limited strikes designed to punish chemical weapons use.

Even those inside Trump's circle who share the president's basic "America First" orientation — think former White House chief strategist Stephen Bannon — have made an exception for Iran. It is the one place where they take their eye off the ball of Sunni extremism, the Salafi jihadism that has attacked the United States, ignore the complexities of nation-building, and pursue the grandiose schemes they have pronounced as failures elsewhere.

Iran is a menace beyond its borders to a degree the other recent examples have not been at the time of our preventive wars, it is true. Yet it is not the greatest threat to the United States. Referring to the trillions of dollars Washington has spent in the Middle East, Trump once observed, "If our presidents had gone to the beach for 15 years, we'd be in a lot better shape than we are right now."